Variously constructed injection needle safety instruments have conventionally been proposed in order to prevent inadvertent sticking of an injection needle into a finger or the like.
For example, Japanese Patent Laying-Open No. 11-57005 (PTD 1) discloses an injection needle safety instrument consisting of a single member constructed to safely be removable from a barrel without sticking of an injection needle into a finger or the like after a syringe is used.
The injection needle safety instrument disclosed in Japanese Patent Laying-Open No. 11-57005 includes a hub and a shield pivotably coupled to each other with a hinge being interposed. After a syringe is used, the hub is fixed to a needle tube of an injection needle constituted of the needle tube and a needle hub, the shield is fixed to the hub by pivoting the shield while the shield covers a pointed end of the needle tube, and the injection needle together with the injection needle safety instrument is removed from the barrel by applying external force to the injection needle safety instrument in this state in a direction across an axial line of the barrel.
Japanese National Patent Publication No. 2007-503871 (PTD 2) discloses an injection needle safety instrument consisting of a single member assembled in advance to an injection needle such that the injection needle does not stick into a finger or the like after a syringe is used.
The injection needle safety instrument disclosed in Japanese National Patent Publication No. 2007-503871 includes a collar and a protection housing pivotably coupled to each other with a hinge being interposed, the collar is fixed in advance to a needle hub of an injection needle constituted of a needle tube and the needle hub, and the protection housing can be fixed to the collar by pivoting the protection housing after the syringe is used, while a pointed end of the needle tube is covered with the protection housing.
Japanese National Patent Publication No. 2005-521537 (PTD 3) discloses various injection needle safety instruments each constituted of a plurality of members assembled in advance to a barrel such that an injection needle does not stick into a finger or the like after a syringe is used.
Many of the various injection needle safety instruments disclosed in Japanese National Patent Publication No. 2005-521537 each include a hub attached to a barrel as well as a manual operation portion and a shield which are coupled to the hub with various links being interposed, and the shield can be fixed to the manual operation portion or the link by pivoting the shield by operating the manual operation portion after the syringe is used, while a pointed end of a needle tube is covered with the shield.